Did the Lower Hudson (N.Y.) Journal News, which recently published a "gun map" showing the names and addresses of registered gun owners, ultimately provide a service for criminals by showing which non-gun-owning homes may be safer to burglarize?

Up until now, gun owners have been the ones protesting the decision last month by the Gannett-owned newspaper, saying it put "in harm's way tens of thousands of lawful license holders," according to the New York State Rifle & Pistol Association.

But a "dumbfounded" Robert Astorino, the top elected official in Westchester County, N.Y., told The Washington Post Wednesday that "the newspaper did all the work" for criminals throughout the lower Hudson Valley area of New York who "are still deciding which house they're going to hit."

Since its publication on Dec. 22 – a week after the shooting of 20 grade-school children and six school staff in Newtown, Conn. – the gun map had fueled debate about journalistic ethics and media advocacy. But Mr. Astorino's comments have raised another contentious issue in the national gun-rights conversation: To what extent does gun ownership deter criminal activity?

Information about gun owners is a central point of disagreement in discussion about the Second Amendment. The federal government does not keep any inventory on who owns guns and for what reasons. It's left to states and counties to register and record people who sign up for concealed carry permits. The only published federal record about gun ownership is the number of background checks the federal government carries out.

Groups like the National Rifle Association have fought against a national gun registry, saying it would invite more gun-control scrutiny without providing any real benefit to public safety. But the local data is public, and the Journal News claims its gun map serves a legitimate purpose.

"I would love to know if someone next to me had guns … so I can deal with that," one Lower Hudson local, John Thompson, told the paper.

Yet critics question the Journal News's motives. Does knowing which neighbors are legally registered gun-carriers make a town safer, or is the map intended to demonize legal gun owners?

Meanwhile, bloggers have published addresses of Journal News employees, and the newspaper has hired armed guards in the wake of perceived threats sent by e-mail. Police have said the e-mails did not contain actionable threats.

The broader question of whether gun ownership deters crime yields vastly divergent – and often contradictory – findings, which activists on both sides have attempted to spin in their favor.

Fact-checking organizations note that the number of concealed-carry permit holders have soared during the past decade and that as many as 53 million US homes contain a gun. Yet violence has declined.

But other research suggests that gun ownership might be linked with crime trends in various ways.

It's "probably true that rising crime leads to a perception of increased threat and, therefore, an increase in the prevalence of gun ownership," Garen Wintemute, director of the Violence Prevention Research Program at the University of California-Davis, told Factcheck.org. It's "also the case that making firearms more available is followed by an increase in firearm crime."

But does the Journal News map put non-gun owners in danger? There is evidence that some criminals are deterred by the possibility of their target being armed.

Forty percent of convicts had at some point decided against a crime because they worried that their victims were packing a gun, according to research by James Wright, a sociologist at the University of Central Florida. "One of the conclusions … was that bad guys do worry about armed potential victims, and to the extent possible try to avoid them," says Mr. Wright, author of "Armed and Considered Dangerous: A Survey of Felons and Their Firearms."

But it is hard to determine whether criminals might go so far as to use the Journal News map, suggests Wright.

"The fact of the matter is most bad guys are criminal opportunists, and they're likely not going to take a map with them when they try to decide, 'Gee, should we burglarize this house because maybe it's the one without a gun?' " he says. "We know full well that [burglars] break into houses because there doesn't seem to be anybody home, but part of that calculation is also, 'There's nobody in there with a 12-gauge [shotgun] ready to cut down on me.' "